Lesson seven, part seven. Tree Falls. I just watched the previous video to get myself in the right state of mind to film this one. When I got to this point in the previous video, this slide, I could actually hear the enthusiasm sort of draining out of my own voice. I could almost slow down the timeline and say How those brain switching off there which is usually a sign that I should rerecord the audio or redo the slide to be less boring or something. In this case, I'm going to use my own unenthusiasm as an object lesson concerning The subject matter itself. What is it? Two arguments against? Against what? Platonism. Well, let's review a bit more from the last video. The last video was officially about snakes on the brain. Pretty exciting stuff. But. It was also about this guy, remember him snakes on the, on the brain plus hogs on eyes. Remember the poor pig who just can't get anywhere, I said I found philosophy of mathematics to be kind of that way top heavy. Intellectually heavy duty, no doubt, Platonists versus anti-Platonists. And yet frustratingly friction-less on the surface. Getting back to the slide I sounded bored about. My point was that Lakoff and Nunez. Remember they're the anti-Platonist cognitive scientists. Have two standard arguments and I find them so unhelpful I can hardly muster the will even to discuss them. Even though they are standard hence important. Science is empirical and naturalistic. Hence Platonism must be wrong. But this is question begging. Because the statement that science is empirical and naturalistic even though science is mathematical and math doesn't seem to be empirical, just assumes that Platonism is somehow wrong. Any argument that just assumes Platonism is wrong is not an argument against Platonism. Platonism is just too weird. This argument has the virtue of being psychologically authentic. People really feel that they just couldn't possibly accept Plato's metaphysical picture. It's too crazy. I am very sympathetic to someone who says that life is too short to worry about such crazy stuff. Even so, that's not an argument against Plato, it's just a dismissal of him. This is really the most general statement of the Lakoff and Nunez cognitive science argument. Let me read it to you. The only access that human beings have to any mathematics at all, either transcendent or otherwise, is through Through concepts in our minds that are shaped by our bodies and brains and realized physically in our neural systems. For human beings, or any other embodied beings, mathematics is embodied mathematics. The thing to notice, in my audible lack of enthusiasm for the argument may have obscured this, is that the argument, if it proves anything, proves way too much. You can substitute any x for mathematics. Snakes, rocks, hogs on ice, ethics and the premise will be true. So if the argument is valid, the conclusion will have to follow. We can only think about anything using our brains. Our thoughts are platform dependent on our brains. It doesn't follow that the things we are thinking about. About snakes, trees, hogs, rocks, ethics are not just embodied but embodied in our brains. Lakoff and Nuñez will surely reply in intense frustration that they obviously aren't arguing that everything we think about is literally in our Brains, that's stupid. That would imply that you could lose weight by thinking about feathers inside of aircraft carriers. That's the most absurd diet plan in the world. I couldn't agree more. And I probably should have been clearer that I'm not attributing any such crazy view to Lakoff and Nunez. My point is not that there is no way to distinguish math from aircraft carriers, but that whatever the proper way to distinguish them is this argument doesn't make it clear. So whatever Lakoff and Nunez real argument is this can't be it. Which will probably annoy, Lakoff and Nunez, even more. They will reply that apples and aircraft carriers are physical, empirical entities, out there in the physical world. Numbers are not. That's what makes it so plausible that mathematics literally comes from our brains whereas aircraft carriers and apples exist outside of our brains. Unfortunately, this obviously begs the question. It just assumes that the only plausible candidates for something outside our minds, our brains, is an empirical something, rather than say, Plato's heaven of forms. I have no problem with someone assuming Plato is wrong because it's so crazy, but if you do that, you aren't refuting Plato. You are simply assuming he's wrong. To end my discussion of Lakoff and Núñez on a more positive note, their book contains lots of interesting stuff. I just think it's misframed as an argument against Plato. They should have called their book something like, on the assumption that math can only come from the brain because it is obviously absurd to suppose that it comes from anywhere else. How could the brain possibly produce something with the distinctive character of mathematics? This would be an example if they took my advice about their title of how these authors could disentangle themselves from metaphysics as much as. Decently possible. Not by saying nothing about it, but by making their assumptions clear. And then doing something, admittedly speculative, within the proper realm of cognitive science. Speculative in a good, empirically hypothetical way, not in an inappropriate, overreaching metaphysical way. Inappropriate for cognitive scientists, that is. Because metaphysicians can be as metaphysically speculative as they want, but not cognitive science. At least not while it's allegedly being a proper empirical science. Confused? Yeah, me too. Okay, here is a passage for which I am sorry to say I can provide no footnote. No scholarly reference. A student of mine a few years back showed me this quote from a standard intro philo- psychology text. I know it's a real textbook. I just don't know, whose textbook it is. In all my attempts to Google it just produced a copy of my own lecture notes from a few years ago. Oh well. If anyone knows the source for this quote, what textbook in psychology is from, feel free to email me. Let me just read the quote. A question often asked in beginning philosophy classes is this: If a tree falls in the forest but nobody hears it, is there a sound? The answer is now clear: No. Sound is caused by waves of molecules The physical event, but the waves themselves are not sound. Sound is a psychological event and hence depends on a nervous system to transduce the physical energy of the waves, to nerve impulses. Without a brain to register the transduced physical energy. There can be no sound. The situation is exactly analogous to the relationships of the wavelength to hue and of amplitude to lightness. Physical properties lead to psychological events, but they are not events themselves. The discipline of psycho physics, charts the relationship between physical events and our experiences of them. I've got a problem with this passage. I'm not going to exactly pick on it. Well, I'm going to pick on it but not because I think there's actually anything wrong scientifically with the discipline of psycho physics. Rather, I want to argue that this argument must. Misrepresent a perfectly sound empirical discipline by making it sound metaphysically dubious, which I'm pretty sure the discipline itself is not. Let me explain. Suppose you say, very reasonably I think, that science has to be about what we can actually experience. Science, properly, is empirical. It's all about things we can experience or things we could at least potentially have empirical evidence of. If physical events can't be experienced and could literally never be experienced. Only experiences can be experienced after all. Then science, can't study physics. I suggest you pause this video and think about how the passage I just read, could be read as implying that physics can't be part of empirical science. Okay, are you confused? Let's just make it real simple. Don't you like my little cartoon model illustration to show you what the natural world is like? Unusually for me I gave it a nice little texturey bits, you can imagine reaching out and touching the bark of the tree and that tactile sensation you would get. You can imagine, here the bird tweeting away so tweetily and the tree, it probably smells nice in the spring, something like that. This is what the world is like, but science actually teaches us that the world is a bit different than this. Still confused? This cartoon says it all so simply. In your mind there all these tastes, sights, sound, touches. Outside your mind physics teaches us there's a lot less. The world of the senses that you live in is in a since mind dependent on you. Who originally said the that tree falls in the forest thing? As it so happens it's an imperialists philosopher George Barkley in the 18th century. But I don't even think it's important to mention his name at this point because I think we all intuitively understand how this picture is supposed to be scientifically plausible. And yet, now we get back to Lakoff and Nunez argument which I complained about. The only mental access that human beings have to X at all, either transcendent or otherwise, is through concepts in our minds that are shaped by our bodies and brains and realized physically in our neural systems. For human beings or any other embodied beings X is embodied X. This is a defense of Lakoff and Nunez. They're saying, our account here is why this picture makes sense. But in order to consistently think through their argument We're going to need to go even further. We're going to need to subtract everything outside of our mind from the picture. Which includes all the, the yellow-skinned human being here. Ultimately what we're going to arrive at is, we're going to get back where we started. We're going to say, this is the world, just as you supposed it would be. Only, it's all in your mind. You're trapped in your own mind. Now, we could take it one step further and say strictly what they said is that the whole world is in your brain, which is quite absurd. Nevertheless, the whole world is in your mind is radical enough. They don't intend to say anything like that. I'm sure the author of the psych test did not intend for their argument to have this radically. Idealist quality to it, but what they didn't do was explain exactly how this radical idealist conclusion. Is to be properly resisted, for some things and not other things. Am I arguing that because we think snakes and trees are real, and mind-independent, that therefore we have to believe that math and ethics are, too? We have to say that everything is outside our minds, or else we'd have to say that everything is inside our minds. No. What I'm saying is more like, be careful. If brain scans about snake thoughts obviously can't prove anything much about snakes themselves. How can brain scans about ethics prove anything much about ethics? I'm not saying they can't, I'm just asking how. Let's get back to Haidt, who I keep wandering away from in these slides. Let me read you some quotes. These are from the beginning of chapter two, from the Happiness Hypothesis, Changing Our Mind. The whole universe is change and life itself is but what you deem it, Marcus Aurelius. What we are today comes from our thoughts of yesterday, and our present thoughts build our life of tomorrow: our life is the creation of our mind. And here's the beginning of the chapter, now I'm reading from Jonathan Haidt himself. The most important idea in pop psychology is contained in the two quotations above. Events in the world affect us only through our interpretations of them. So if we can control our interpretations, we can control our world. The best selling self help advisor of all time, Dale Carnegie writing in 1944, called the last eight words of the Aurelius quote Eight words that can transform your life. Let's read those eight words again. Life itself is but what you deem it. In the previous video, I said that Jonathan Haidt employs an empiricist metaphysical rhetoric and I am now illustrating that point. The whole world is literally in my mind. George Barkley, the original tree falls in the forest guy. Affirmed that metaphysical conclusion quite strongly. It is literally true that trees only exist in your mind, your world consists entirely of ideas. It's literally absurd to think that there could be anything except an idea That you could ever be in contact with. Science can't be about anything beyond our ideas, because they're the only things that we can ever experience. Thus, if Haidt is serious about this, if he really wants to go the full George Berkeley with regard to life is but what you deem it. Then he's got a bold Matrix Hypothesis to rival Plato's own. A matrix hypothesis with an opposite moral. Since I'm trapped in my mind, looking at the tree in my mind. And listening to the bird of my mind tweet the tweets of my mind. There is literally no conceivable metaphysical escape from this cave of my own mind. Might as well think happy thoughts about the place. After all, it's a world of pure thought. They might as well be pure happy ones, if I can work it out that way. I don't think Haidt wants to say that, which raises the question. What does he want to say? What is he talking? Is he talking pop psychology? Or cutting edge cognitive science? Or is he branching out into metaphysics? Or what? I would say there's an awful lot of pop psychology in Haidt and I don't mean that in a bad way. But Plato isn't going to disagree with that stuff. Pop-psych stuff is mostly pretty obvious all that psych ever does is make it a little bit more precise. Haidt says this, Plato would agree with it. Suppose someone says, if you think happy thoughts the world will look happier to you. Whereas if you're depressed. The whole world will look depressing. Is Plato going to deny that? No, I can actually quote you passages from the dialogues in which he himself says that. I'm not going to bother you because you can just take my word for it that Plato is not going deny an obvious insight like that. Pop psych is mostly pretty obvious and psych just sometimes verifies it in the lab. Gives us a precisely. Calibrated degree of its truth. Now cog-, cognitive science is going to want to go a bit beyond that providing us something actually surprising. Something that we can actually prove in the lab. Hadit isn't going to want to go that far, but he's going to stop short of metaphysics. That is I don't think he's going to want to Fight with Plato on this ground. Plato says we can escape from the cave of appearance but I, the impurest metaphysician know that I am trapped in my own mind. I don't think Haidt wants to say that even though his rhetoric suggests he wants to say that. This means that rhetorically Haidt and Plato are poles apart but substantively as I've been emphasizing they can be made to sound rather similar. And so, in the next and final video for this lesson, I want to try to say what their difference, substantively, really comes to.
